The feminine mallow sawfly begins her assault on a mallow by utilizing a saw-like egg laying appendage referred to as an ovipositor to carve small slits within the leaf’s floor. Every egg-slits receives an egg. Tiny leaf- munchers difficulty from the eggs, feed, and go by means of six larval phases. Their feeding first creates tiny holes in leaves referred to as shot holes, however as they develop, so too does their urge for food and shortly giant hunks of tender tissue disappear down their gullets, abandoning solely shredded leaves and skeletal stays consisting of powerful leaf veins. As soon as their feasting is completed, larvae transfer to the bottom of the plant to pupate on decrease stems and within the soil. From the pupae emerge contemporary grownup wasps able to discover a mate, lay eggs, and resume the assault on mallow. In southern states there could also be as many as six generations annually, however fewer happen in Maryland. Luckily, mallow sawflies by no means actually developed a honest style for cotton, okra, or rose of Sharon, however hollyhocks, decorative mallows, and marsh-mallow are undoubtedly on the menu. By midsummer, leaves of those beauties could also be shredded.
So, what are you able to do to forestall a plague of those tiny tormentors? A number of styles of hibiscuss, together with Hibiscus acetosella, H. aculeatus, and H. grandiflora, are famous to be immune to this pest. One other technique to foil the sawfly is to examine your hibiscus on a weekly foundation and easily pluck larvae from the plant and toss them within the compost the place they’ll change into meals for the ravenous horde of predatory invertebrates dwelling there. Whereas insecticidal sprays can be found to kill sawfly larvae, excessive visitation charges of pollinators and different useful bugs to the hibiscus flowers make this a sketchy choice.
Two wonderful articles, “Analysis of Twelve Genotypes of Hibiscus for Resistance to Hibiscus Sawfly, Atomacera decepta Rohwer (Hymenoptera: Argidae)” by David W. Boyd, Jr. and Christopher L. Cheatham, and “The sawfly Atomacera decepta, a pest of Hibiscus” by H. H. Tippins have been used to organize this episode. We thank Karin Burghardt, whose eager observations of mallow sawflies served because the inspiration for this episode.