228 
Psyche 
[Vol. 88 
instars. Following one experiment on the alarm response, 5 fifth 
instar nymphs from a second aggregation were released, one at a 
time, slightly above the leaf just vacated by the first aggregation. 
Four of the fifth instars moved directly up the stem and onto the 
newly occupied leaf, and the remaining nymph wandered about, 
first on higher leaves and then on the vacated leaf before moving to 
the occupied leaf. Other experiments showed that nymphs would 
reaggregate after they were separated by the experimenter. Need for 
physical contact might explain this adequately, but the presence of 
an aggregation pheromone should not be ruled out. Reaggregation 
is essential if the alarm response is to occur repeatedly. 
female’s behavioral maturation 
Preliminary experiments (Kearns 1980) indicate that females 
undergo behavioral maturation from the time of oviposition through 
egg hatch and early development of the nymphs. Females at 
different stages of development were substituted for females which 
were attending aggregations of nymphs. Only those substitutes 
which had attended aggregations of their own behaved normally 
during an alarm response. When females which were still oviposit- 
ing were used as substitute mothers, they either avoided the alarmed 
nymphs or failed to interact with them. 
CHLOROFORM EXTRACT 
A chloroform extract of G. solani nymphs proved to be as 
effective in eliciting an alarm response as a fifth instar nymph 
squeezed with forceps or squashed on filter paper. Crushed adults 
also released the alarm pheromone, but the nymphal response was 
slower by a minute or less, to a crushed adult than to a crushed 
nymph. Preliminary attempts were made to test for alarm pher- 
omones in 3 other tingids available locally: Corythucha ciliata, the 
sycamore lace bug; Corythucha cydoniae, the hawthorne lace bug; 
and Corythucha marmorata, the chrysanthemum lace bug. Nymphs 
of each species showed an alarm response to a crushed nymph of 
the same species. There were also cross responses between G. solani 
and each of the three species of Corythucha. Since not all three 
species of Corythucha overlap in time, it will be necessary to rear the 
insects in the laboratory or to make extracts of each for testing cross 
responses. 
