Miridae ~ Plant Bugs

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The mirids constitute the largest family of true bugs. The majority feed on plants (a few are predatory) and some can be major pests. Because they feed by sucking out plant juices, they don't create ragged edges on leaves but instead cause leaves to discolor, shrivel, or have spots. Many plant bugs are not all that numerous and these do not cause problems, but when a population surges, then the damage to certain plant species, especially crops or ornamentals, can be substantial. Plant bugs are on the small side, with the largest reaching only about 7 mm in length. The smallest that I've noticed are more like 3 mm or less. Most are about 5 mm. As a group, they are recognized by the presence of an obvious cuneus, or triangular patch at the rear of the thick part of the upper wing, and one or two rounded cells in the wing membrane, which are usually more obvious on one side than the other because the wings overlap each other. It often helps to note what kind of plant a mirid is feeding on, as a number of species are rather host-specific and there are databases with this information. Poecilocapsus lineatus Poecilocapsus lineatus nymph Calocoris barberi Some of the most often noticed mirids are, as would be expected, on the large side and also colorful. They resemble small beetles at a glance, especially the small and colorful leaf beetles. One of the prettiest mirids is the Four-lined Plant Bug (Poecilocapsus lineatus). It can also be quite a garden pest. The yellow color can also be light green, but the head is always orange, even on nymphs. This species feeds on a variety of plants, sometimes in large numbers. A similar looking insect is not so widespread but is quite common in our area. This is Calocoris barberi. It also has stripes and is usually yellow, but may also be a darker dull orange. It feeds mainly on Mexican Hat (Ratibida columnaris) but is sometimes found on the related coneflowers and Rudbeckia species. The image included here happens to be on a completely different plant in the legume family, but the insect shows up much better and they are often rather camouflaged on their usual host plant flowers. Metriorhynchomiris dislocatus: color variations Metriorhynchomiris dislocatus has an impossibly long name and no common moniker. It is just a little smaller than the previous species but has a similar shape. Although an all-black color variation can occur in this species, the ones in our area are all marked with gold, orange, or red. They are very shiny, almost looking like they are wet. The antennae are also distinctive, with black segments at the base and the last two outer segments being white. Neocapsus cuneatus: color variations A bit smaller than M. dislocatus, Neocapsus cuneatus has similar color variability. In this insect, though, the cuneus (triangular patch on the wing) is often, but not always, the contrasting color. It can also just be black. These are not as common as some plant bug species and I only see them occasionally. Taedia species Taedia species Taedia species nymph There are at least two species of Taedia, recognized by their longer body shape, fairly thick lower antennal segments, a thick felt-like hairiness, and the presence of a pair of velvety spots on the pronotum. Even nymphs have the thick antennae. One species is all red with darker markings, which range from very light to quite dark. The hairy pelt on this insect seems to almost obliterate the differences between the colors. The other species has more defined colors and is gold to red and black, with the most typical color being orange. It has more of a velvety texture. Lopidea major nymph Many species of bugs are difficult to distinguish from other members of the same genus, partly because colors are a little variable and sometimes the differences are quite minimal. Lopidea species are one of those groups. They all have the same look: long and rather flattened body with black markings on a base of gold, orange or red. There is one species in our area that can be found on numerous plants and flowers and it has a wide black mark on its entire back and light orange sides. One species, though, is very host-specific and so can be recognized by when and where it shows up. Lopidea major is present only in the spring (the early nymphs start to appear at the beginning of March) and feeds on Texas Mountain Laurel (Sophora secundiflora). This species was also called Lopidea texana but that is now considered to be a junior synonym. These bugs are very gregarious and often disfigure a lot of leaves on the trees when they feed. However, they don't seem to affect the health of the plants in spite of their numbers. Lopidea major Lopidea species There are other red and black mirids that have a similar body shape to Lopidea but they are not as flattened. This has been a challenging group to identify, even to the genus level, as there are not many labeled images available. I suspect a number of our species have restricted ranges and are not found by researchers elsewhere. Prepops has a red scutellum that is quite raised. It also has a red head but the rest of the body is a matte black. Prepops species Oncerometopus species maybe another Oncerometopus species A species in the genus Oncerometopus is yet another similar insect, with black markings on red. It is not particularly common. There is another species that might be in the same genus, or perhaps our single species is just quite variable. It is a mostly red bug, with wings that barely cover the abdomen. This could be because all I've seen are females, but it is quite noticeable that the abdomens are very rotund. These bugs show up in fields on flowers in the Compositae family. A very curious little bug feeds on prickly pear cactus in our area. Hesperolabops gelastops can often be found in great numbers on some plants. This mirid has a red head and black body with white borders. It is only about 5-6 mm in length. The odd thing about this bug is its stalked eyes. They stick up quite a bit above the head. Nymphs are red and their eyes only have short stalks. Hesperolabops gelastops Hesperolabops gelastops nymph Deraeocoris species Some bugs are not particularly common and only show up occasionally. A species in the genus Deraeocoris is one such insect. Its body is very dark brown with colorless antennae, legs and wing membrane. The body texture is shiny but with many fine punctures in the entire surface. It appears to have a relatively small head and constricted neck.

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