Saturday, 12 November 2011

Ground Beetles: The nocturnal insecticides

Ground beetles too do the work of insecticides during dark hours. Though I had often seen them in my childhood in the backyard of our house and in our fields during daytime after rains. These beetles live in the soil and generally seen on the ground but they devour insects on plants during night. Ground beetles as a group is the largest groups of beetles.Although members of the group differ slightly in their body shape and color, but most are shiny and black(some are metallic), and have ridged wing covers. Body size varies from 7 mm to 13 mm. Forewings are hard elytra with linings. Another phenotypic trait common to ground beetles is a smaller head than thorax, and threadlike antennae.  Ground beetles have well developed sickle shaped serrated mandibles. They use their biting type mouth parts to devour other insects. Trochanta is absent, so it can run very fast.
Adults are active at night and tend to hide under rocks during the day time. They will run when exposed. They come out at night to feed on other insects. Likely targets include caterpillars, root maggots, snails and other soft bodied insects. Most species don’t use their wings, but a few may fly to lights at night.
Ground beetles undergo complete metamorphosis. Female ground beetles lay their eggs in the soil. Eggs hatch into larva that feed upon insects in or on the soil under debris. Depending on the species, there may be several generation per year. Sometimes they invade the house if food become scarce or moisture condition are unfavorable. Ground beetles larvae like adults, are important predators. The larvae live below the ground, where they use their large pincher like mandibles to devour soil-dwelling insects. Both adults and larvae act as insecticides as they feed on larvae of other insects including pests.
Adults may wander into homes by crawling through small openings or under doors. They will not stay inside, they prefer the outdoors. Since the ground beetles are beneficial insects, control is not warranted. However if they are creating a nuisance, move or remove hiding places next to the houses such as log piles, mulch and debris. Beetles found indoors may be swept up and discarded.
                      If beetles are creating nuisance by flying to lights at night, repositioning the lighting or changing white light to yellow may reduce attraction.
Thus these beetles can help me in diminishing the poison residues in vegetables, fruits and grains consumed by me. No doubt if permmitted they can also help farmers in reducing their expenditure on insecticides.

Friday, 7 October 2011

PRAYING MANTIS: A PREDATORY PESTICIDE !

I have been fascinated with the ootheca of praying mantis since my childhood days. My grand mother used to keep it safely in niche in a wall of our anscetral home in my village, Nandgarh. On enquiring about this egg sac, she oftenly told us that this is the "Giddad ki Sundi"( navel of jackal). Now I am much surprized to know that this navel of jackal is nothing but ootheca viz-a-viz egg mass of a predatory insect-praying mantis. Because of its primarly preying nature, I started spelting it as preying mantis but my father corrected me by explaining that praying stands for its posture and mantis for prophet or fortune teller. Praying mantids in various colors of camouflage are very common in most of the crops grown in Hariyana but luckily or unluckily they are often mistaken as grasshoppers(God's horse or cow) by the people here. But actually they are more closely related to cockroaches and termites than grasshoppers and stick insects.
Practically praying mantises prey and eat any living organism they can successfully capture and devour. But insects may be herbivores, neutrals and carnivores form the main diet. They eat beetles, weevils, bugs, moths, butterflies and various insects available in our crops. Thus they act as natural pesticides for controlling the various leaf eating loopers and semiloopers, fruit eating bollworms, leaf folders and stem borers, bugs including notorious mealybug, weevils like grey weevil, and beetles like chefer, brown flower beetle and insect pests like jassids, aphids, hoppers. Most of the species of praying mantises are known to engage in cannibalism meaning thereby that they also consume praying mantises as food.
Thus praying mantises act as insecticides by way of preying and consuming so many insect pests in our crops otherwise we have to kill them by spraying chemical insectcides from market. We need not to multiply & market them for insect control but to recognize them and safegaurd them. They are available in each and every crop and that to totally free. Such heros of our war against pests should not remain unsung. The woman farmers from Nidana(Jind) have done this job meticulously.
Different species of praying mantises commonly noticed in Haryana:

Wednesday, 28 September 2011

DRAGONS AS INSECTICIDES!!

Dragonflies are neither dragons nor flies but they are odonatian insects. These are so common during rainy season in our distt. Jind( Hariyana) that every one have to see them flying in sky over parks in city and over crop canopies in the villages. They are called as helicopters by the children in Haryana. Naughty and creative children used to catch them, tie a thread to their legs and enjoy them as game of kite flying. Our elders say that flying height of the dragonflies is an advance indicator of the intensity of the rains to come. They used to tell us that if dragonflies are flying very low near the ground then good chances for heavy rains in the area. Light rains or clouds will be there if these insects fly at medium height just above the crops. And their flights very high in the sky is a symbol of clear sky. In China and Japan these insects have generally been taken as symbol of courage & strength but in Europe and America except native tribes, these insects had often been taken as evils.

But hard fact at ground is that these dragonflies definitely do themselves the work of insecticides. They spend most of their time in the air for preying and mating.The dragonflies are general predators and hunts in groups. These natural insecticides in the form of dragonflies kills mosquitos, flies, moths, beetles, weevils and so many small insects. And so many of them are vegetarians causing losses to our crops in various proportions.
These dragonflies lay their eggs in water may be in ponds, lakes and crops like paddy. The nymphs known as naiads are also nonvegetarians and prey upon mosquito larva, plant hoppers and eggs of various insects available  in water or near water level on plants. Myself had seen the dragonflies in the air preying upon chefer beetles, moths of paddy leaf folders and paddy stem borers. If our farmers stop using insecticides in the early stages of paddy and give a safe chance to these dragons for breeding in paddy feilds, the dragons can definitely help them in controlling leaf folder and stem borers at zero cost. And finally will help the society by reducing the poison in their food plates.