SUSTAINING THE WORLD THROUGH SCIENCE AND TECHNOLOGY

Summary of Economic Importance


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The Delphacidae are the most diverse and economically important family of planthoppers.  Fifty-five species are known pests on 25 crops (Wilson & O’Brien 1987) including 5 of the top 10 major world food commodities (Table 1).  Delphacids cause damage both through direct feeding damage, injection of saliva (potentially leading to hopperburn) and as vectors of plant viral diseases (e.g., Nault 1994, Kuniata et al. 1994, Narayana & Muniyappa 1996, Garat et al. 1999, Remes-Lenicov & Virla 1999a, b; Laguna et al. 2002, Brentassi & Maldonado 2002, Liu et al. 2002, Dhileepan & Croft 2003, Rubia-Sanchez et al. 2003, Dintinger et al. 2005, Costamagna et al. 2005, Yin et al. 2005, Wilson 2005, Grilli 2006, Grimshaw & Donaldson 2007).   About 30 species are known plant disease vectors (Table 2).  Most plant pathogens vectored by delphacids (Table 3) appear to be viruses (including the pathogen for the emerging Ramu stunt disease of sugarcane, Braithwaite et al. 2007), except the Saccharosydnini are reported to vector phytoplasmas (formerly known as mycoplasma-like organisms [MLOs], which are bacterial). 

Of particular importance is the impact of planthoppers on rice production.  The Ricehoppers blog (http://ricehoppers.net/) reports especially regarding planthoppers in that context.  The International Rice Research Institute (IRRI) recently (23-25 June 2008) held a conference on planthopper problems and control in Asia (synopsis here). The press release for the conference, called planthoppers a “major threat to Asian rice production” and noted that:

“Problems caused by planthoppers, a major type of rice pest that can destroy one-fifth of a harvest, have intensified across Asia in recent years. Major outbreaks in Vietnam in 2007 contributed to recent dramatic rises in the cost of rice, which have threatened to push millions of people deeper into poverty. If not effectively controlled, these pests could hamper rice production and help keep prices high.”

 

Available online is:

Heong, K.L. and B. Hardy, (eds). 2009. Planthoppers: New Threats to the Sustainability of Intensive Rice Production Systems in Asia. International Rice Research Institute, Los Baños, Philippines.


Table 1. Top world agricultural crops with delphacid pest taxa (2004 FAO data)

Harvest
ranking

Crop

Million metric tons 2004

Delphacid pest genus (e.g.)

Plant diseases vectored

1

Sugar Cane

1,324

Perkinsiella, etc.

Fiji disease, yellow leaf phytoplasma

2

Maize

721

Peregrinus, etc.

Maize stripe, mosaic, rough dwarf

3

Wheat

627

Javesella, etc.

Wheat striate mosaic, stripe virus

4

Rice

605

Nilaparvata, etc.

Grassy stunt, Hoya blanca, Rice stripe

9

Barley

154

Laodelphax, etc.

Yellow striate mosaic, yellow dwarf


The “Ricehoppers” blog is intended to provide the “latest information and issues relevant to managing rice planthopper problems” (but it seems to have gone unmodified since February 2015). Of greatest significance is to rice is Nilaparvata lugens, about which Herdt (1987) reports estimated losses of $1.06 billion from rice crops in Southeast Asia each year and over $5 billion as the equity weighted value of output foregone due to N. lugens.  While I have not found more recent calculations of these figures, the significance of major rice pests is unlikely to be declining at a time when concerns over world rice shortages are a topic of popular news media.  If anything, it appears that concerns over rice planthoppers are increasing, with recent news items such as the “Sichuan Rice Disaster” in 2007 where migratory planthoppers caused the “…worst rice pest disaster in 16 years. Rice plant hoppers have already attacked 5.2 million mu (about 0.85 million acres) rice fields in 85 counties and county-level cities across the province.”  (Nilaparvata lugens is not native to Sichuan, but the species is well-known for its migratory behavior; e.g., Holt et al. 1989, Riley et al. 1991, 1994; Turner et al. 1999, Otuka et al. 2005a, b; Furuno et al. 2005). The New York Times (May 18, 2008), reported on the threat of planthoppers to world food supplies at a time when research money is being cut.  The main planthopper rice pests in Asia – Nilaparvata lugens and Sogatella furcifera – are not established in the New World.

In the New World, the key delphacid pests Nilaparvata lugens, Sogatella furcifera and Laodelphax striatellus have been intercepted at ports, but never established.  Recently one of the Taro planthoppers (Tarophagus collocasiae) has recently been established in FloridaPerkinsiella saccharicida (the vector of Fiji gall in sugarcane) was established in North America in the 1980s (fortunately without the plant pathogen).  Peregrinus maidis appears to be endemic (but that has been disputed).

Table 2. Delphacid Plant Disease Vectors (updated from Wilson 2005).

Delphacid species

Pathogen

Select Hosts

Region

Caenodelphax taepae

UHBV

Plantain signalgrass

NT

Chilodelphax albifascia (= Unkanodes (C.) albifascia)

NCMV, RSV, RBSDV

Rice

PA-E

Delphacodes catilina (as "Toya catilina") MMV (as ACSV) Wheat, Oats, Barley, Rye, Corn IM

Delphacodes kuscheli

MRCV

Maize

PA-W

Dicranotropis hamata

MRDV, OSDV, PGSV

Grasses (Oats, etc.)

HO

Eumetopina flavipes

Ramu stunt (evidently a virus)

Sugarcane

AP

Javesella discolor

OSDV

Grasses (Oats, etc.)

HO

Javesella dubia

EWSMV, OSDV

Grasses (Wheat, etc.)

HO

Javesella obscurella

EWSMV, OSDV

Grasses (Wheat, etc.)

HO

Javesella pellucida

EWSMV, OSDV, MRDV (experimentally BYSMV)

Grasses (Wheat, etc.)

HO

Laodelphax striatellus

BYSMV, MIMV, MRDC, NCMV, RSV, RBSDV, WCSV, WRSV; Maize streak dwarf (?) nucleorhabdovirus

Grasses (Wheat, etc.)

IM, PA

Megadelphax sordidulus

PGSV

Grasses (Timothy, etc.)

PA-W

Metadelphax propinqua

CCSV, MRDV, BYSMV

Maize, Bermudagrass, &c.

All

Muellerianella fairmairei

NCMV

Grasses (Oats, etc.)

PA-W

Nilaparvata bakeri

RGSV, RRSV

Rice

IM

Nilaparvata lugens

RGSV, RRSV

Rice

AP, IM

Nilaparvata muiri

RGSV

Rice

IM

Peregrinus maidis

FMMV, IMMV (MIMV), MMV, MSSV, MSV, MSpV, Maize line virus

Maize, Sorghum

AF, AP, IM

Perkinsiella saccharicida

FDV

Sugarcane

AF, AP

Perkinsiella vastatrix

FDV

Sugarcane

AF, AP

Perkinsiella vitiensis

FDV

Sugarcane

AP

Saccharosydne saccharivora SCYLP* Sugarcane NT

Sogatella furcifera

PSV, SRBSDV

Grasses, Rice

AP, IM

Sogatella kolophon

BWSpV, DiSV, MSSV

Maize, grasses

AF, AP, IM

Sogatella vibex

ERSV, FMMV, MRDV, MSSV

Maize, grasses

AP, IM, PA

Tagosodes cubanus

EHBV, RHBV

Maize, coconut

AF, NT

Tagosodes orizicolus

MRCV, RHBV

Rice, Echinochloa, grasses

NA, NT

Tarophagus prosperina

CBV

Taro

AP, IM

Terthron albovittatum

RSV, RBSDV

Rice, Echinochloa

IM, PA-E

Unkanodes sapporonus

NCMV, RSV, RBSDV

Rice

IM, PA-E

Unkanodes tanasijevici

IMMV (MIMV)

Maize, grasses

PA-W

Unkanodes tanasijevici (as Ribautodelphax notabilis)

IMMV (MIMV), MRDV, RBSDV

Maize, grasses

PA-W

       

Sources: Wilson (2005) et cite, plus Lockhart (1986), Kuniata et al (1994), Arocha et al. (2005), Costamagna et al (2005); Braithwaite et al. (2007); Mattio et al. (2008); Universal Virus Database, v. 4. http://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/
For virus abbreviations see below.  Biogeographic Region Abbreviations: AF-Afrotropical, AP-Australo-Pacific, HO-Holarctic, IM-Indo-Malayan, NA-Nearctic. NT-Neotropical, PA-Palearctic, PA-E-Eastern Palearctic, PA-W-Western Palearctic.

* A phytoplasma - all others are viruses.


Of the 30 delphacid species known to be crop disease vectors, only 8 are known from continental United States.  Of these, one (Perkinsiella saccharicida, a sugarcane specialist) is introduced from the Australo-Pacific region (Sosa 1983, 1985; Meagher et al. 1991, 1993; Emeljanov 1994), and a second (Metadelphax propinqua) may have been introduced near the end of the 19th century (Gonzon and Bartlett 2008).  Two other species are introduced: Harmalia anacharsis (found secondarily on rice) and Conomelus anceps (Holdom et al. 1989, Wooten et al 1993, Wheeler and Hoebeke, 2008).   The latter species, evidently introduced from Europe into Nova Scotia, illustrates that even species intuitively unlikely to become invasive may be introduced.  Conomelus is a rush (Juncus spp.) specialist, and ordinarily brachypterous and sedentary.     One species, Megamelus scutellaris, is likely to be has been introduced as a biological control agent of water hyacinth in southeastern USA (USDA 2010).  the Taropest Tarophagus collocasiae was found in Florida in 2015, but apparently was established in Jamaica in 2011 and Cuba in 2014.

Hawaii has had 10 immigrant delphacid species including 4 pest species (Peregrinus maidis (on corn), Perkinsiella saccharicida (on sugarcane), and two Tarophagus species (on taro); Asche 1997).   The introduction of Perkinsiella saccharicida was particularly significant since it resulted in a total annual output of sugar for the Hawaiian Islands to be reduced by 16% within 2 years of introduction (in 1900; Swezey 1936).


Table 3. Pathogens known to be vectored by delphacid planthoppers. Names are being updated to conform with ICTV, and links are given to VIDE or DPVweb (links to ICTV appear to go to the index).

Pathogen

Pathogen Name

ACSV African Cereal Streak Virus (apparently = MSV = MMV)

BWSpV

Brazilian wheat spike disease (tentative Tenuivirus, =Wheat white spike disease) (see Caetano al 1970)

BYSMV

Barley yellow striate mosaic cytorhabdovirus (also here)

CBV

Colocasia bobone disease (?) rhabdovirus

CCSV

Cynodon chlorotic streak nucleorhabdovirus

DiSV

Digitaria striate (?) cytorhabdovirus

EHBV

Echinochloa hoja blanca virus (= rice hoja blanca tenuivirus)

ERSV Echinochloa ragged stunt oryzavirus

EWSMV

European wheat striate mosaic virus (= wheat European striate mosaic (?) tenuivirus)

FDV

Sugarcane Fiji disease fijivirus

FMMV

Finger millet mosaic nucleorhabdovirus

IMMV

Iranian maize mosaic (?) nucleorhabdovirus (Maize Iranian mosaic virus (MIMV)

  Maize line virus
MIMV Maize Iranian mosaic virus (see  IMMV above) (ICTV taxonomic proposal)
MMV Maize mosaic nucleorhabdovirus (VIDE Rhabdoviridae) (see also here)

MRCV

Mal de Rio Cuarto fijivirus (also here [.doc])

MSV 

Maize stripe virus (=MMV and ACSV above)

MSpV Maize stripe tenuivirus (FL extension bulletin) (ICTV)

MRDV

Maize rough dwarf fijivirus 

  Maize streak dwarf (?) nucleorhabdovirus

MSSV

Maize sterile stunt virus (= Barley yellow striate mosaic cytorhabdovirus (also here))

NCMV

Northern cereal mosaic virus

OSDV

Oat sterile dwarf fijivirus (and here)

PGSV

Phleum green stripe (?) tenuivirus

PSV

Pangola stunt fijivirus

RBSDV

Rice black-streaked dwarf fijivirus (and here)

RGSV

Rice grassy stunt tenuivirus

RHBV

Rice hoja blanca tenuivirus

RRSV

Rice ragged stunt oryzavirus

RSV

Rice stripe tenuivirus

(none)

Ramu stunt (appears to be a virus despite assertions to the contrary; see Braithwaite et al. 2007)

SCYLP Sugarcane yellow leaf phytoplasma (see Arocha et al 2005)
SRBSDV Southern Rice Black Streak Dwarf fijivirus (new!) (see Zhou et al. 2008)

UHBV

Urochloa hoja blanca tenuivirus (unassigned here)

WCSV

Wheat chlorotic streak virus (same as Northern Mosaic cereal virus)

ZRSV

Wheat rosette stunt virus (= Cereal northern mosaic cytorhabdovirus)

 

The following table summarizes the delphacid species intercepted at US ports from 1986 to 2008.

 

Table 4. Delphacid interceptions at US ports 1986-2008 (USDA-APHIS-PPQ; F. Kuehn, DE Dept Ag, pers. com.)

Identification

# intercept.

Asiraca clavicornis**

1

Calligypona sp.**

1

Delphacodes puella

1

Delphacodes sp.

18

Laodelphax striatellus**

1

Liburnia sp.*

1

Nilaparvata lugens **

9

Nilaparvata sp.

4

Peregrinus maidis

13

Perkinsiella saccharicida ***

1

Saccharosydne sp.

1

Sogata sp.*

1

Sogatella sp.

1

Stenocranus sp.

1

Tagosodes sp.

3

Tarophagus prosperina** (genus now ***)

1

Family ID only

349

total

407

*Genera of dubious standing.

** Taxa not occurring in North America.

***Taxa adventive to North America.

 

Since 2009, Stuart McKamey has graciously agreed to save delphacid specimens intercepted at ports and sent to the USNM Sytematics lab for identification. 

Recent interceptions (2007-2009) were reported as follows (McKamey Identifications)

Genus Species #
Delphacidae spp.
51
Neosydne spp nr leahi
1
Nilaparvata spp. ? lugens
1
Peregrinus maidis
3
Stenokelisia angusta
4

Also 1 Dictyopharidae and 1 cicadellid nymph

Of the specimens listed above as recent interceptions - I have checked/reviewed the following:

Delphacidae

 Delphacinae: Tropidocephalini

 - Columbiana sp. () - intercepted Miami Air CBP, FL from Columbia 5 Nov 2009 Antirrhinum sp (snapdragon)

 - Columbisoga sp. FL Miami Air CPB, ex Columbia, 17.vi.2011, on Ruscus sp. (Asparagaceae) (APMFL111686766010)

 - Columbisoga sp. FL Miami Air CPB, ex Columbia, 28.iv.2010, on Chrysanthemum sp., with cut flower (APMFL101181151024)

Delphacinae: Delphacini

 - Chionomus sp. () - Intercepted Miami AFB, FL from Columbia, 5 Aug. 2009, on Grevillia sp. (Proteaceae)

 - Chionomus sp. () - intercepted Miami Air CBP, FL from Peru, 15 May 2009 on Lactuca satvia (Lettuce) (2 specimens, other was Tagosodes).

 - Chionomus balboae (1♂) - FL Miami Air CPB, from Dominican Republic, 8.vii.2011, Capsicum sp. (Pepper), APMFL111896766003

 - Chionomus havanae - intercepted Otay Mesa CBP, CA from Mexico, 3 Nov. 2008 Carica papaya (on fruit) (papaya).

- Delphacini (), possibly Delphacodes lutulenta - intercepted San Luis CBP, AZ from Mexico 6 Jul 2009, on automobile.

- Delphacini (), possibly Delphacodes lutulenta - intercepted San Luis CBP, AZ from Mexico 6 May 2009, on Origanum majorana (Marjoram).

- Delphacini (), possibly Sogatella kolophon - intercepted Philadelphia CBP, PA from Costa Rica, 8 May 2009 on Ananas comosus (Bromeliaceae, Pineapple).

- Delphacini (), possibly Delphacodes nr campestris - intercepted  Otay Mesa CBP, CA from Mexico 1 Feb. 2009, on Mentha sp. (mint).

- Delphacini (), possibly Delphacodes latidens; intercepted AZ, Nogales CPB, from Mexico; on Zea mays (APTAZ101306168011)

- Delphacini (), intercepted San Francisco CBP, CA from Mexico 12 Jan 2010 on Ocimum basilcum (basil).

- Delphacini (), intercepted San Luis CBP, AZ, from Mexico, 27 Jul 2009 in travelers bag of hitch hiker.

- Delphacini (), intercepted Calexico CPB East, CA from Mexico 19 Nov 2008 on Petroselinum crispum (Parsley).

- Delphacini (), intercepted Calexico CPB East, CA from Mexico 22 Dec. 2008 on Coriandrum sativum (Coriander).

- Delphacini (), possibly Euides sp., intercepted FL, Miami Sea CBP, from Panama, 15.xi.2010 ex Ananas comosus (Pineapple), with fruit (APMFL103191485001)

- Delphacini (), poss. Metadelphax propinqua, intercepted Otay Mesa CBP, CA from Mexico 11.ii.2011 on Coriandrum sativum (Coriander) (APSCA110426661001).

- Delphacini (), poss. Metadelphax propinqua, intercepted AZ, San Luis CPB, AZ, from Mexico; 27.v.2010, on Thymus vulgarus (common thyme); APTAZ101472913012.

- Delphacini (), intercepted Miami Air CBP, FL from Guatemala, 22 Mar 2009, on Lactuca sp. (Lettuce)

- Delphacini (), poss. Metadelphax propinqua, intercepted Calexico CPB East, CA from Mexico 21 Feb 2009 on Anethum graveolens (Dill).

- Delphacini (), poss. Metadelphax propinqua, intercepted NY NY JFK CBP, from Ecuador, 20.iii.2011, on Ocimum basilicum (sweet basil) (APNNY11079474003)

- Delphacini (nymph), intercepted JFK CPB NY, from Columbia 20 Sept 2008, Origanum sp. (a mint)

- Delphacini (),  possibly Nothodelphax sp., intercepted Los Angeles CBP, CA from Columbia 08 Apr 2010 on Alstroemeria sp. (Peruvian Lily or Lily of the Incas, Alstroemeriaceae) (the genus can not be confirmed by a female; if it is Nothodelphax it did not originate form Columbia but probably is from the local fauna; the genus is very common in California).

- Delphacini (), possibly Sogatella furcifera (but the specimen appears too pale); intercepted Houston Sea CBP, TX from Viet Nam, 12 Nov 2010, with equipment (APHTX103192700001)

- Delphacini (), possibly Sogatella kolophon; Intercepted FL, Miami Air CPB, from Ecuador, 17.xi.2010; on Solidago sp. (goldenrod) (APMFL103215868013)

- Delphacini (), possibly Toya nigra, FL Miami Air CPB, ex Columbia, 16.ii.2011, ex Cut flowers, APMFL110471952007

- Delphacini (), possibly Toya sp. FL Miami Air CPB, ex Peru 13.v.2009, Origanum majorana (sweet marjoram) (APMF091333336036)



- Delphacodes nr campestris () - intercepted Otay Mesa CBP, CA from Mexico, 3 Nov. 2008

- Delphacodes nr campestris (2 ) - intercepted Calexico, CA from Mexico 19 Dec 2008; 3 specimens: 2 on Coriandrum sativum (Coriander); 1 on Petroselinum crispum (Parsley).

- Delphacodes nr campestris () - intercepted Calexico, CA from Mexico 9 Dec 2008; on Brassica oleracea var. acephala (kale or collard greens).

- Delphacodes nr campestris () - intercepted San Luis CBP, AZ from Mexico 26 June 2008 on Citrullus lanatus (watermelon).

 - Delphacodes fulvidorsum (2, 1♀), intercepted Otay Mesa CBP, CA from Mexico, 5 Jan 2009, Brassica chinensis (bok choy).

 - Delphacodes prob. nigripennis (Crawford) () - intercepted Otay Mesa CBP, CA from Mexico 25 Oct 2009 on Spinacia oleracea (spinach).

 - Delphacodes prob. nigripennis (Crawford) () - intercepted Otay Mesa CBP, CA from Mexico 4 Dec 2008 on Ocimum basilcum (basil).

 - Delphacodes pacifica () - intercepted Otay Mesa CBP, CA from Mexico, 5 Jan 2009, on Origanum sp.

 - Euides weedi () - intercepted Port Manatee CBP, FL from Honduras 19 Feb 2010 on Cucumis melo (Melon).

 - Euides weedi () - intercepted TX Dallas/Fort Worth CPB, ex from Netherlands, 12.v.2010; Hydrangea sp. on cut flower stem APHTX101326191004 (note: Euides weedi is a North American species)

- Laodelphax striatellus (1♀) - Intercepted TX, Houston Sea CBP, from Italy; 26.x.2010; with tiles (APHTX102992700007)).

- Megamelus sp. (2 males, poss. electrae; will check) - intercepted Miami Air CPB, FL from Haiti, 25 Jan 2008, 'at large'.

- Megamelus sp. (1♀) - intercepted Miami Air CBP, FL, from Columbia, 10.vii.2010, ex Dianthus sp., with cut flowers (APMFL101913353006)

- Metadelphax propinqua () - intercepted Calexico, CA, from Mexico, 31 Oct 2008; on Brassica oleracea var. cephala.

- Metadelphax propinqua () - intercepted Otay Mesa, CA, from Mexico, 2 Dec 2009; on Anethum graveolens (Dill)

- Metadelphax propinqua (2♂) - intercepted A, Calexico, CBP East, from Mexico, 16 April 2010; on Brassica chinensis (pak choi); APSCA101071551006 (specimens are washed-out pale, but clearly this species).

 

 - Nilaparvata lugens - intercepted Tampa CBP. FL from Viet Nam, 16 Feb 2010, with ceramic wares.

 - Nilaparvata lugens - intercepted CA, Los Angeles CBP; from Singapore, 30.v.2009; ex Dendrobium sp. (Orchid) APLCA091504874001.

- Nilaparvata probably lugens (1), GA Atlanta CPB, from South Korea, 25.11.2010, Nephelium lappaceum (rambutan); (APAGA103295500003)

 - Peregrinus maidis - intercepted San Francisco, CA, 2 Mar. 2007, from Mexico, on Anethum graveolens (Dill).

 - Peregrinus maidis - intercepted Nogales, AZ from Mexico, on corn (Zea mays); 6.v.2008 AND 7.v.2008 AND 29.vii.2009.

 - Peregrinus maidis - intercepted Los Angeles CBP, CA from Peru, 26 Apr 2010 on Lycopodium sp. (clubmoss).

 - Peregrinus maidis - intercepted Miami Air CBP, FL from Costa Rica, 16 Dec. 2009 on Agapanthus sp. ("Lily of the Nile", Agapanthaceae).

 - Peregrinus maidis - (1 male, 2 nymphs) intercepted Miami Air CBP, FL from Haiti 13.ix.2009 ex Zea mays (APMFL092596563001)

 - Peregrinus maidis - (1) CA, San Diego, CBP, from Ecuador, 20.vi.2011, ex Ananas comosus (Pineapple) (APSCA111716593003)

- Sardia rostrata - intercepted Honolulu predeparture PPQ, Hawaii 27 Jan 2009 on Ocimum sp. (a mint; [basal?) (this is the specimen identified as Neosydne above; this species is introduced to Hawaii)

 - Tagosodes sp. () poss. approximatus (not cubanus or orizicolus)- intercepted Miami Air CBP, FL from Peru, 15 May 2009 on Lactuca satvia (Lettuce) (2 specimens, 2nd was Chionomus)

- Tagosodes orizicolus () - intercepted Philadelphia CBP, PA from Costa Rica, 27 Apr 2010 Cucumis melo (with fruit) (Melon).

- Tagosodes orizicolus () - intercepted Miami Air CBP, FL from Columbia, 30 Jan 2010 on Ocimum basilcum (basil).

- Tarophagus colocasiae (1, 1) intercepted JFK CPB, NY from Columbia on 21 Apr 2008, on Origanum sp. (a mint) (This is an odd interception - Tarophagus, the taro planthoppers, are Old World).

- Tarophagus colocasiae (2, 2, 3 nymphs) - Intercepted NV, Los Vegas CBP, from Philippines, 22.v.2009; on unknown plant; (APLNV091460593001; TSU 1003399)

 

- Toya nigra (), Intercepted San Francisco CPB from Mexico 17 Nov 2008 on Origanum vulgarae (oregano).

 

Dictyopharidae

1 nymph (possibly Dictyophara europaea): - intercepted from JFK CPB, NY, from Netherlands, 2 Dec 2009 on Berzelia sp. (a shrub in the Bruniaceae).

last edited 06 Jan. 2016.