SUSTAINING THE WORLD THROUGH SCIENCE AND TECHNOLOGY

Seasonality


Planthoppers are most diverse and abundant in mid to late summer, but like many other insects, males often will mature somewhat before females.  This may be simply because they are slightly smaller, or perhaps to allow them to disperse to reduce chances of inbreeding, or perhaps for some other reason.  Mortality of males tends to be higher than females in any given population (i.e., females live longer), thus early in the year, populations would tend to be male biased, but later in the year populations would tend to be female biased. Giri and Freytag (1983) in study of Delphacodes lutulenta in the greenhouse found that males lived 27 (+/- 2.4) days as adults, versus 33.9 (+/- 3.3) days for females.

Only a few studies have directly addressed the seasonality of North American delphacids.  Davis and Gray (1966) studied the distribution and seasonality of insects in the coastal marshes of North Carolina.  Generally, they found that delphacids, depending on species were found beginning in in mid to late April or early May, built up in abundance until July or August, and then declined.  In that system, delphacids overwintered as a late instar nymph or adult. they matured in spring, mated and laid eggs on their host plants in late winter or early spring (Jan.-March), afterwards the adults died.  Delphacids could be found in the salt-march system all year, but lowest abundance was in march, and highest in July August.

Wheeler (2003) studied the life history on an unusual delphacid, Javesella opaca, that feeds on the moss Polytrichastrum alpinum (an exceptionally unusual host!), in the southern Appalachians.  He found for this species that late instars overwintered and developed to adults by mid- to late March (macropters were observed in these adults, but not in subsequent generations).  first instars appeared from mid- to late May, with adults (initially all males) appearing from mid-June to early July.  First instars of a second (overwintering) generation were observed in early August.

The common delphacid Delphacodes campestris produced two full generations and a partial third (overwintering) generation in Nebraska (Whitmore et al. 1981).  In the laboratory, this species averaged 31 days for males and 35 days for female to progress from egg to adult (at 25 deg C).

Gratton and Denno (2003) presented seasonality of Prokelisia planthoppers in Maryland salt marshes with resepct to multi-trophic interactions.  Sosa et al. (1986) presented information on the seasonality of Perkinsiella saccharicida.  Bartlett & Deitz (2000, for Pissonotus) and Gonzon et al. (2007) presented the seasonal distribution for their target planthopper taxa.  Additional information on delphacid seasonality were provided by Weber and Wilson (1981, for Liburniella ornata) and Wheeler and Bartlett (2006, for Delphacodes campestris and D. lutulenta)

References

Bartlett, C. R. and L. L. Deitz. 2000. Revision of the New World delphacid planthopper genus Pissonotus (Hemiptera: Fulgoroidea). Thomas Say Publications in Entomology: Monographs. 234pp.

Davis, L. V. and I. E. Gray. 1966. Zonal and seasonal distribution of insects in North Carolina salt marshes. Ecological Monographs 36(3): 275-295.

Giri, M.K., and P.H. Freytag. 1983. Biology of Delphacodes lutulenta (Homoptera: Delphacidae). Annals of the Entomological Society of America 76(2): 274-277.

Gonzon, A. T., C. R. Bartlett, and J. L. Bowman. 2007 (dated 2006). Planthopper (Hemiptera: Fulgoroidea) diversity in the Great Smoky Mountains National Park. Transactions of the American Entomological Society 132(3-4): 243-260.

Gratton, C. and R. F. Denno. 2003. Seasonal shift from bottom-up to top-down impact in phytophagous insect populations. Oecologia (Berlin) 134(4): 487-495.

Sosa, O., Jr., R. H. Cherry and R. Nguyen. 1986. Seasonal abundance and temperature sensitivity of sugarcane delphacid (Homoptera; Delphacidae). Environmental Entomology 15(5): 1100-1103.

Weber, B. C. and S. W. Wilson. 1981. Seasonal and vertical distributions of planthoppers (Homoptera: Fulgoroidea) within a black walnut plantation. Great Lakes Entomologist 14(2): 71-75.

Wheeler, A. G., jr. and C. R. Bartlett. 2006. Delphacodes campestris (Van Duzee) and D. lutulenta (Van Duzee) (Hemiptera: Fulgoromorpha: Delphacidae): Association with common hairgrass, Deschampsia flexuosa (Poaceae), and notes on habitats, seasonality, and taxonomy. Proceedings of the Entomological Society of Washington 118(2): 395-403.

Whitmore, R. W., K.P. Pruess, and J.T. Nichols. 1981. Leafhopper and planthopper populations on eight irrigated grasses grown for livestock forage. Environmental Entomology 10(1): 114-118.