Ae. Pinkney et al., Effects of the mosquito larvicides temephos and methoprene on insect populations in experimental ponds, ENV TOX CH, 19(3), 2000, pp. 678-684
The nontarget effects of Abate(R) 4E (44.6% temephos) at 0.054 kg of active
ingredient (a.i.) per 1 ha and of Altosid(R) Liquid Larvicide (5% methopre
ne) at 0.011 kg a.i./ha were investigated in 18 experimental ponds (average
area. 202 m(2); maximum depth, 0.7 m) at Patuxent Wildlife Research Center
Laurel, Maryland, USA. Ponds were sprayed three times at 3-week intervals.
Six ponds were sprayed with Abate, six with Altosid, and six with distille
d water. Two insect-emergence traps per pond collected for 7 d and were the
n harvested 1 d before each spray and 13 to 14 days afterward. A repeated m
easures analysis of variance (ANOVA) revealed significant reductions in Sha
nnon diversity, equitability, and numbers of individuals, species, and fami
lies in the Abate ponds relative to controls. Significant reductions also o
ccurred in Ephemeroptera, Odonata, Diptera, Chironomidae, and Chaoborus sp.
Hester-Dendy samplers were installed before spray one and harvested 16 d a
fter spray three. Based on one-way ANOVA, Shannon diversity, equitability,
and number of Ephemeroptera and Chironomidae were significantly reduced in
the Abate ponds. Emergence data indicate only isolated cases with significa
nt reductions in the Altosid ponds relative to controls, and the Hester-Den
dy data indicate no significant differences between the Altosid and control
ponds.