Rl. Lampman et Rj. Novak, OVIPOSITION PREFERENCES OF CULEX-PIPIENS AND CULEX RESTUANS FOR INFUSION-BAITED TRAPS, Journal of the American Mosquito Control Association, 12(1), 1996, pp. 23-32
The number of egg rafts oviposited by Culex pipiens and Culex restuans
in infusion-baited ovitraps varied with the type of infusion substrat
e, infusion age, method of infusion preparation, and calendar date. In
one or more tests, more Culex egg rafts were collected from water inf
used with Kentucky bluegrass sod, mixed grass clippings, straw, or a c
ommercial rabbit chow than from a water control. Infusions prepared wi
th oak leaves, maple leaves, and sod soil were ineffective as Culex ov
iposition attractants; however, alfalfa infusions ranged from marginal
ly effective to unattractive. Rabbit chow infusions required one or mo
re reinfusions before becoming active oviposition lures when prepared
in unconditioned (unused) ovitraps. Infusions prepared in conditioned
ovitraps (those that had previously contained the same type of infusio
n) had shorter delay periods. Effective oviposition lures for Culex sp
ecies included continuous infusions, such as sod and sod grass, and th
ose in which the substrate was infused in the water for only a brief p
eriod (24-48 h), such as infusions of rabbit chow and mixed grass clip
pings. The percentage of egg rafts from Cx. restuans was usually great
er in sod and grass infusions than in rabbit chow infusions, whereas C
x. pipiens showed a slight preference for rabbit chow infusions over s
od and grass infusions. The temporal shift in relative oviposition act
ivity of the 2 Culex species (cross-over) varied from year to year and
between sites in one year.