Nature biographies; the lives of some every-day butterflies; moths; grasshoppers and flies . happens that one kind becomes over-whelmingly abundant. And when this happens Nature calls to her aid these parasiticplants which commonly makeshort work of the offending in-dividuals. Aside from the Bacteria, themost important plant parasites ofinsects belong to a group calledEntoiiiophtJwrccs by the botan-ists. Most of them belong tothe genus Empusa. In theirstructure these plants are alliedto the moulds, but nearly all ofthem have the striking peculi-arity that they can develop onlyupon certain form
Nature biographies; the lives of some every-day butterflies; moths; grasshoppers and flies . happens that one kind becomes over-whelmingly abundant. And when this happens Nature calls to her aid these parasiticplants which commonly makeshort work of the offending in-dividuals. Aside from the Bacteria, themost important plant parasites ofinsects belong to a group calledEntoiiiophtJwrccs by the botan-ists. Most of them belong tothe genus Empusa. In theirstructure these plants are alliedto the moulds, but nearly all ofthem have the striking peculi-arity that they can develop onlyupon certain forms of living in-sects. Every one has seen theEmpusa tliat attacks the com-mon house-fly; it is this plantthat causes the dead fly to adhereto the walls and window panes;the halo of white powder that commonly surroundsthe insect consists of the reproductive spores of thefungus. A strikino- illustration of mans indebtedness to theseEmpusas in keeping in check outbreaks of injuriousinsects has lately been seen in Maryland, Delaware, andother North Atlantic states. In many regions in this 92. Fic. 89. — Dead Locust clinging to Goldenrod. Locust Mummies. territory the growing of peas for canning is an importantindustry. Until lately there has been very little difficultyin raising the crop, few insects having become trouble-some to the plant. In 1899, however, a plant-louse, oraphis, appeared suddenly on the vines over a large area,and soon destroyed much of thecrop. In 1900 the attack was re-peated with results that were almostequally disastrous. Even the entomologists at firstwere puzzled to determine wheresuch enormous numbers of the plant-lice came from so suddenly. Forsome time it was supposed to be anundescribed species; it belonged tothe genus Nectarophora, and thespecific name destructor was pro-posed for it. It was later found,however, to be a species long knownin Europe as Nectarophora pisi, andthe careful studies of several officialentomologists soon showed that thepests
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectinsects, bookyear1901
