THREE SPOTTED PSYLLIA Psyllia trimaculata Crawford Psyllia astigmata Crawford This species (Fig. 43) is a very conspicuous feature of the locality, both nymphs and adults appearing in such numbers and distributions as to attract attention.
The nymphs were first noted as abundant on the Fire cherry Prunus pC2Insylvanica) where the white cottony or woolly masses covering the bodies of the insect and occurring on the under surface of the leaves formed a very conspicuous object. (See Fig. 44.) Nymphs observed July 3 were in final instar and adults were observed emerging July 7. All adults noted July 7 and S were males, and agreed closely with descriptions and figures of astigmata Crawford, for which no larval history has been recorded. The woolly nymphs bear close resemblance to P. floccosa Patch. described from alder, but adult characters appear to he sufficient to separate the two species. While a very few scattered nymphs have been well restricted to the fire cherry so this may be counted the preferred if not the only host plant. Early nymphs have not been observed but undoubtedly occur and develop during June, probably hatching from eggs which have wintered in buds or hark.
Nymphs of the last instar are light green. the wing pads whitish, broadly ovate, the head short, wider than long, as wide as pro thorax. Antennae with terminal segment and apex of preceding segments, 5-6-7, black, 3-4 tinged at tip, 1-2 pale. Ocelli close to eye, dark; eyes blackish; pronotnm short, beak light yel lowish, dark at tip; wing pads of meso- and meta-thorax expanded, wider than abdomen ; abdomen as wide as long and sub-truncate behind, bearing a large mass of flocculent waxy filaments, easily detached but when the insect is moving giving the appearance of animated bits of fluffy cotton. The appearance of these cottony masses is well shown in the photo plate (Fig. 43). There are long whitish bars on the margin of wing pads and abdomen; the legs with few hairs.
Adult males were appearing fairly common July 7 and S and females on the 8th and 9th. Nymphs were still present on fire cherry July 20 but practically all have emerged as adult and very few of the cottony masses remain as compared with a week earlier. Many of the adults collected on fire cherry as well as from other vegetation have the orange red or red markings given as char acteristic of 3-9noculata, later appearing adults seeming to furnish a greater proportion of the red marked individuals. Extended
search for nymphs has failed to show any on alder or other plants on which adults are common. On August 1 no nymphs were to be found but occasional tufts of the cottony secretions and molted skins were still hanging to the leaves.
Adults taken July 28 from cherry — agreeing in every detail, except color, with earlier specimens — are nearly all deep blood red on the dorsal lobes of pro- and meso-thorax. As earlier col lections and reared specimens for the early part of the month were less distinctly marked it appears probable that the different coloration is a seasonal feature due possibly to later maturity 'in nymphal stage, or to difference in temperature or other conditions at time of emergence. No evidence that there is change in color after are once fully mature was found as uncolored specimens kept in confinement either if bred or collected from trees showed no decided change of color when kept several days with food supply.
Adults both with and without the bright red marks have been taken in large numbers from a great variety of trees, including birch, willow, aspen, maple, and on none of which have the floccu lent nymphs been seen alive. Those taken on Prunes have the thorax of yellowish white or light greenish with three prominent orange or red spots on the three lobes ; the abdomen is green ; tip of upper genital valve, tarsal spurs, claws and antennae, except at base, are black; eyes black. The evidence given in brief above seems to warrant the conclusion that P. as suspected by Crawford, is only an uncolored form of P. maculata and as P. maculate has priority, the former species becomes a synonym.
Tt seems also fair to infer from the seasonal history and the habits of related species that eggs are deposited in fall, probably in or around the buds of fire cherry, where they remain till the Following summer when they hatch, and develop as the cottony covered nymphs of June and July.
Chermes pinifoliae Fitch. This species, illustrated in Fig. 42, page 100, is not discussed in detail, our observations being quite fragmentary, hut it may he mentioned that females ovipositing on pine leaves were seen to extrude eggs and. after laying a mass of to 40 eggs, to turn around and deposit another mass, proving very definitely that Fitch's conclusion that eggs were not extruded but held within abdominal walls, the dead insect adhering to the leaf, is not the rule for the species.